Hidden Arsenal 1 (HA01) introduces the "Ice Barrier," "Mist Valley" and "Worm" Archetypes to the TCG as well as further support for the "Ally of Justice," "Neos," "Kuriboh," "Cyber Dragon," "Flamvell" and "X-Saber" cards. Highly sought after cards from this set include Mist Wurm and Brionac, Dragon of the Ice Barrier.